Answer:
Both search a firm surface that can anchor them.
Step-by-step explanation:
The central idea of lines 1-12 is that sea stars are similar to humans because both are always seeking a firm surface that can anchor or support them. The sea stars attach themselves to the surface of the sea floor in order to remain in one place which is suitable for them. The human do the same way, they stick to one place where they get more benefits and more sources of needs. The author also compares a sea star missing an arm to a human missing a limb. For a sea star, losing an arm is part of life but for a human to loss a limb will change its whole life.